[NFC] Test that shows unprofitability of instcombine with bit ranges

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336078 91177308-0d34-0410-b5e6-96231b3b80d8

Author: Max Kazantsev

test/Transforms/InstCombine/icmp_sdiv_with_and_without_range.ll

@@ -0,0 +1,32 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -instcombine -S < %s | FileCheck %s
+
+; Test that presence of range does not cause unprofitable transforms with bit
+; arithmetics, and instcombine behaves exactly the same as without the range.
+
+define i1 @without_range(i32* %A) {
+; CHECK-LABEL: @without_range(
+; CHECK-NEXT:    [[A_VAL:%.*]] = load i32, i32* [[A:%.*]], align 8
+; CHECK-NEXT:    [[C:%.*]] = icmp slt i32 [[A_VAL]], 2
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %A.val = load i32, i32* %A, align 8
+  %B = sdiv i32 %A.val, 2
+  %C = icmp sge i32 0, %B
+  ret i1 %C
+}
+
+define i1 @with_range(i32* %A) {
+; CHECK-LABEL: @with_range(
+; CHECK-NEXT:    [[A_VAL:%.*]] = load i32, i32* [[A:%.*]], align 8, !range !0
+; CHECK-NEXT:    [[B_MASK:%.*]] = and i32 [[A_VAL]], 2147483646
+; CHECK-NEXT:    [[C:%.*]] = icmp eq i32 [[B_MASK]], 0
+; CHECK-NEXT:    ret i1 [[C]]
+;
+  %A.val = load i32, i32* %A, align 8, !range !0
+  %B = sdiv i32 %A.val, 2
+  %C = icmp sge i32 0, %B
+  ret i1 %C
+}
+
+!0 = !{i32 0, i32 2147483647}